Random.int64 bound returns a random integer between 0 (inclusive)
and bound (exclusive). bound must be greater than 0.

valfloat : float -> float

Random.float bound returns a random floating-point number
between 0 (inclusive) and bound (exclusive). If bound is
negative, the result is negative or zero. If bound is 0,
the result is 0.

valbool : unit -> bool

Random.bool () returns true or false with probability 0.5 each.

Advanced functions

The functions from module State manipulate the current state
of the random generator explicitely.
This allows using one or several deterministic PRNGs,
even in a multi-threaded program, without interference from
other parts of the program.